In connection with the safety seat belts known today, one end of the belt is permanently retained by a spring-loaded roller in a wound and strained position in a way such that with slow pullout motions of the seat belt, the seat belt is fastened and the occupant is held by the belt against the force of the spring. When a sudden motion occurs, that is by high accelerations, the seat belt is blocked by the spring due to the mass moment of inertia as it may occur, for example, when the vehicle is suddenly retarded due to contact with an obstacle or another vehicle and the belt is retained at its two ends, permitting the spring to perform the retaining function it is expected to perform.
Normally, the seat belts are currently fitted by the automobile manufacturers and mounted in different ways. The use of said belts, which are permanently under spring tension, is considered an inconvenience in many cases particularly because the belt is placed across the torso or upper part of the chest, thus causing many drivers to have a feeling of being constricted in an unpleasant way.
The prior art sought an additional attachment for motor vehicles which attachment made it possible to loosen the initial stress exerted on the belt by the spring, so that the user is not constricted by the belt pressure.
Typical prior art devices are disclosed in U.S. Pat. No. 4,297,467 granted Oct. 13, 1981 to Frantom and U.S. Pat. No. 4,484,766 granted Nov. 27, 1984 to Buchmeier. Those devices required the manufacture, assembly and mounting of several specially machined interfitting metal members. This was a costly solution to the problem of seat belt strain relief, and which engendered unwieldy installation, and provided the undesirable addition of metal frame members mounted on the inside of the automobile adjacent the driver and passengers.
Now there is provided by the present invention a readily retrofitted and universally adaptable seat belt tension relief device which eliminates the aforesaid prior art problems associated with specially machined interfitting metal members. SUMMARY OF THE INVENTION
A seat belt tension relief device is formed with an adjustable length elastic member which at one end is pivotally mounted adjacent the door frame while at the other end is formed with a flexible adjustable member which encompasses the seat belt at the portion of the user's torso. The device is substantially of flexible material construction. When not in use the device is readily removed or stowed.
In use, the device portion which encompasses the seat belt readily disengages from the seat belt under high accelerations so that the seat belt holds in its intended fashion.